Communication devices which operate over different frequency bands are considered desirable, in private markets and enterprise, and particularly in the public-safety arena where such devices are used by such agencies as police departments, fire departments, emergency medical responders, and military to name a few. The use of separate antennas to cover different frequency bands is often not a practical option in view of the portability and size limitations of portable devices. There is need for multiband antenna structures that can cover multiple bands providing for an overall wideband operation. However, achieving multiband functionality can prove quite challenging in the portable communication device domain. The incorporation of separate antennas and matching networks may result in a prohibitively large structure, unsuitable for portable devices having limited size constraints. Efficiency of operation and co-existence interference issues are also major concerns in multiband antenna designs. The addition of frequency bands after product release can also be problematic, as designs are typically based on a limited, fixed predefined list of frequency bands.
Accordingly, there is a need for an improved antenna configuration providing improved multiband capability for a portable communication device.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.